U.S. patent number 6,827,808 [Application Number 10/240,384] was granted by the patent office on 2004-12-07 for method and apparatus for removing tablets from blister packs.
This patent grant is currently assigned to Wright, Fenn & Co. LTD. Invention is credited to John David Fenn.
United States Patent |
6,827,808 |
Fenn |
December 7, 2004 |
Method and apparatus for removing tablets from blister packs
Abstract
An apparatus is provided for removing tablets from a blister
pack including formations for receiving the tablets and a
rupturable foil member which seals the formations. The foil member
is rupturable to allow removal of the tablets from the blister
pack. The de-blistering apparatus works essentially by using an
adhesive coated tape to mount and draw the blister pack through a
depressing station and a foil removal station. In the depressing
station, the foil which seals the tablet within the formations is
ruptured and in the foil removal station the ruptured foil is
removed from the blister pack to free the tablet.
Inventors: |
Fenn; John David (Surrey,
GB) |
Assignee: |
Wright, Fenn & Co. LTD
(Surrey, GB)
|
Family
ID: |
9888552 |
Appl.
No.: |
10/240,384 |
Filed: |
October 21, 2002 |
PCT
Filed: |
March 22, 2001 |
PCT No.: |
PCT/GB01/01250 |
371(c)(1),(2),(4) Date: |
October 21, 2002 |
PCT
Pub. No.: |
WO01/72589 |
PCT
Pub. Date: |
October 04, 2001 |
Current U.S.
Class: |
156/247; 156/761;
221/82; 221/84; 221/85 |
Current CPC
Class: |
B65B
69/0058 (20130101); Y10T 156/12 (20150115); Y10T
156/1961 (20150115); Y10T 156/1052 (20150115) |
Current International
Class: |
B65B
69/00 (20060101); B32B 035/00 () |
Field of
Search: |
;156/247,344,584
;221/76,79,81,82,84,85,86 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Osele; Mark A.
Attorney, Agent or Firm: Smith-Hill and Bedell
Claims
What is claimed is:
1. Apparatus for removing tablets from a blister pack including a
formation for receiving a tablet and a backing layer which seals
the formation and is rupturable to allow removal of the tablet, the
apparatus including a flexible adhesive member, means for bringing
at least a part of the backing layer of the blister pack into
contact with the flexible adhesive member, and means for depressing
the formation to rupture the backing layer sealing the formation,
when the backing layer sealing the formation is in contact with the
flexible adhesive member.
2. Apparatus according to claim 1, wherein the blister pack
includes a plurality of formations each receiving a respective
tablet and a substantially planar member from which the formations
protrude.
3. Apparatus according to claim 2, wherein when the backing layer
is bought into contact with the flexible adhesive member, the
backing layer adheres to the flexible adhesive member, and wherein
means are further provided for separating the flexible adhesive
member in contact with the ruptured backing layer from the
associated formation, a part of the ruptured backing layer
remaining in contact with the flexible adhesive member and thereby
releasing the tablet.
4. Apparatus according to claim 1, wherein the flexible adhesive
member includes an adhesive coated tape.
5. Apparatus according to claim 4, wherein means are provided for
conveying the blister pack on the tape between a depressing station
where the formation is depressed to rupture the backing layer and a
backing layer removal station where a part of the ruptured backing
layer is removed from the blister pack.
6. Apparatus according to claim 5, wherein the means for conveying
the blister pack on the tape includes a tape collector roller which
rotates to draw the tape through the depressing station and the
backing layer removal station and wherein tape for drawing through
the depressing station and the backing layer removal station is
drawn from a tape cartridge located upstream of the depressing
station and a carrier plate having a substantially planar upper
face is located between the tape cartridge and the depressing
station.
7. Apparatus according to claim 6, wherein the carrier plate
includes a substantially straight edge adjacent the depressing
station, and wherein the tape passes over the carrier plate with
its adhesive coated face oriented away from the plate, such that a
blister pack located on the carrier plate is received on the
adhesive coated face of the tape.
8. Apparatus according to claim 7, the means for depressing the
formation include means for gripping an edge of the blister
pack.
9. Apparatus according to claim 8, wherein the driven roller is
located at the depressing station adjacent to and slightly spaced
from the edge of the carrier plate, and the size of the space
between the driven roller and the edge of the carrier plate is
adjustable.
10. Apparatus according to claim 9, wherein the driven roller draws
the blister pack between the roller and the tape, and as the
blister pack is drawn under the driven roller, the driven roller
depresses a formation of the blister pack, thereby pushing an
enclosed tablet towards the flexible adhesive member and rupturing
the backing layer.
11. Apparatus according to claim 10, wherein a freely rotatable
roller is provided downstream of and spaced from the driven roller,
the adhesive coated tape passing over the freely rotatable roller,
and the freely rotatable roller and the driven roller being
positioned such that the adhesive coated tape when being drawn
between the two rollers is angled at between 30 and 60.degree. to
the carrier plate.
12. Apparatus according to claim 11, wherein the backing layer
removal station includes means for guiding the blister pack away
from the tape towards a tablet collection container including a
receptacle, provided with an opening through which individual
tablets may pass.
13. A method for removing tablets from a blister pack including a
formation for receiving the tablets and a backing layer which seals
the formation and is rupturable to allow removal of the tablets,
the method including the steps of bringing at least a part of the
backing layer of the blister pack into contact with a flexible
adhesive member and depressing the formation to rupture the backing
layer sealing the formation, when the backing layer sealing the
formation is in contact with the flexible adhesive member.
14. A method according to claim 13, wherein the method further
includes the step of separating the flexible adhesive member in
contact with the ruptured backing layer from the associated
formation, a part of the ruptured backing layer remaining, in
contact with the flexible adhesive member and thereby releasing the
tablet.
15. A method according to claim 14, wherein the flexible adhesive
member includes an adhesive coated tape.
16. A method according to claim 15, wherein the method includes the
step of conveying the blister pack on the tape between a depressing
station where the formation is depressed to rupture the backing
layer and a backing layer removal station where a part of the
ruptured backing layer is removed from the blister pack.
17. A method according to claim 16, wherein the method includes the
step of gripping an edge of the blister pack in the depressing
station.
Description
The invention relates to apparatus for removing tablets from
blister packs of tablets.
Blister packs are a very common means of packaging pharmaceutical
tablets and may also be used for packaging swimming pool chemicals,
gardening tablets, etc. Such blister packs conventionally include a
generally planar member of a plastics material, provided with a
series of formations for receiving the tablets. A tablet is
inserted into each of the formations, the open ends of which are
sealed by means of a backing layer of aluminium foil or other
breakable material, which is attached to the plastics material.
Each tablet is thus sealed in its own formation until use, when the
plastics formation is depressed by finger pressure and the tablet
is forced out through the backing layer.
In some establishments, such as large dispensing chemists, there is
a need to de-blister large numbers of blister packs of tablets, for
example for storage or for making up into individual packs
including all a patient's prescribed tablets. Generally, the mass
de-blistering of blister packs in order to remove the tablets is
done manually and shop assistants carrying out the de-blistering
may damage their fingers and fingernails.
According to the present invention there is provided apparatus for
removing tablets from a blister pack including a formation for
receiving a tablet and a backing layer which seals the formation
and is rupturable to allow removal of the tablet, the apparatus
including a flexible adhesive member, means for bringing at least a
part of the backing layer of the blister pack into contact with the
flexible adhesive member, and means for depressing the formation to
rupture the backing layer sealing the formation, when the backing
layer sealing the formation is in contact with the flexible
adhesive member.
Preferably the blister pack includes a plurality of formations each
receiving a respective tablet. Preferably the blister pack includes
a substantially planar member from which the formations
protrude.
Preferably when the backing layer is bought into contact with the
flexible adhesive member, the backing layer adheres to the flexible
adhesive member.
Preferably means are further provided for separating the flexible
adhesive member in contact with the ruptured backing layer from the
associated formation, a part of the ruptured backing layer
remaining in contact with the flexible adhesive member and thereby
releasing the tablet.
Preferably the flexible adhesive member includes an adhesive coated
tape.
The tape may have a thickness of between 0.05 mm and 0.2 mm, and
preferably has a thickness of about 0.11 mm. The tape may have a
breaking load of between 10 and 30 N/cm and a maximum elongation of
between 110% and 130%.
Preferably the tape is a polyvinyl chloride tape.
Preferably the adhesive is a pressure sensitive adhesive. The
adhesion of the tape to steel is preferably between 2.5 and 5 N/cm
and most preferably about 3.6 N/cm. The adhesion of the tape to
itself is preferably about 0.6 N/cm.
Preferably means are provided for conveying the blister pack on the
tape between a depressing station where the formation is depressed
to rupture the backing layer and a backing layer removal station
where a part of the ruptured backing layer is removed from the
blister pack.
Preferably the means for conveying the blister pack on the tape
includes a tape collector roller which may rotate to draw the tape
through the depressing station and the backing layer removal
station. The tape collector roller may include a central driven
rotatable member which may be between 6 mm and 12 mm in diameter.
The tape collector roller preferably further includes an outer
substantially cylindrical tape receiving portion which preferably
has a diameter of between 60 mm and 120 mm and most preferably
about 80 mm. When the central member is rotated, preferably tape is
drawn onto and wrapped around the outer tape receiving portion.
Preferably tape for drawing through the depressing station and the
backing layer removal station is drawn from a tape cartridge
located upstream of the depressing station. The tape cartridge may
comprise a roll of tape.
Preferably a carrier plate having a substantially planar upper face
is located between the tape cartridge and the depressing station.
The carrier plate may receive a blister pack to be de-blistered.
Preferably the carrier plate includes a substantially straight edge
adjacent the depressing station.
Preferably the tape passes over the carrier plate with its adhesive
coated face oriented away from the plate, such that a blister pack
located on the carrier plate is received on the adhesive coated
face of the tape.
Preferably a guide roller is located above and spaced from the
carrier plate. The guide roller may be made of a soft material for
lightly pressing the blister pack against the tape. The guide
roller may be freely rotatable.
The means for depressing the formation may include means for
gripping an edge of the blister pack. These means may include a
rotatable driven roller. The driven roller may be located at the
depressing station adjacent to and slightly spaced from the edge of
the carrier plate. The size of the space between the driven roller
and the edge of the carrier plate is preferably adjustable.
Preferably the adhesive coated tape is drawn under the driven
roller. Preferably the driven roller draws the blister pack between
the roller and the tape. The driven roller may be located about 1
mm from the tape. The driven roller may have a diameter of between
6 mm and 1 mm and preferably has a diameter of about 8 mm.
Preferably as the blister pack is drawn under the driven roller,
the driven roller depresses a formation of the blister pack,
thereby pushing an enclosed tablet towards the flexible adhesive
member and rupturing the backing layer. Preferably the rupture is
at the leading edge of a part of the backing layer sealing the
formation. Preferably the substantially straight edge of the
carrier plate mounts and locates the blister pack during this
process.
Preferably the driven roller has a non-stick outer surface.
Preferably the adhesive coated tape passes under the driven roller
with its adhesive coated face oriented upwardly.
Preferably a freely rotatable roller is provided downstream of and
spaced from the driven roller. Preferably the adhesive coated tape
passes over the second freely rotatable roller. The freely
rotatable roller is preferably located about 40 mm to 70 mm away
from the driven roller. Preferably the driven and freely rotatable
rollers are positioned such that the adhesive coated tape when
being drawn between the two rollers is angled at between 30 and
60.degree. to the carrier plate.
Preferably the tape collector roller is located downstream of the
freely rotatable roller. The tape collector roller may be located
generally under the freely rotatable roller. The tape collector
roller may be located such that the adhesive coated tape when
passing from the freely rotatable roller to the tape collector
roller is angled at between 90.degree. and 330.degree. to the tape
located between the driven and freely rotatable rollers.
The tape collector roller and the driven roller in the depressing
station may be driven by a common drive means. The central driven
rotatable member of the tape collector roller may be connected by
drive means such as a chain, belt, etc., to the driven roller in
the depressing station.
The backing layer removal station may be located in the region of
the freely rotatable roller. The backing layer removal station may
include means for guiding the blister pack away from the tape
towards a tablet collection container. The tablet collection
container may include a receptacle provided with an opening through
which individual tablets may pass. Preferably the opening is
sized/positioned such that the blister pack does not pass
therethrough in normal use.
The apparatus may further include a receptacle for collecting empty
blister packs, located adjacent to the tablet collection
receptacle. The receptacle may include an opening through which the
blister pack may pass.
According to the invention there is further provided a method for
removing tablets from a blister pack including a formation for
receiving the tablets and a backing layer which seals the formation
and is rupturable to allow removal of the tablets, the method
including the steps of bringing at least a part of the backing
layer of the blister pack into contact with a flexible adhesive
member and depressing the formation to rupture the backing layer
sealing the formation, when the backing layer sealing the formation
is in contact with the flexible adhesive member.
The method may further include the step of separating the flexible
adhesive member in contact with the ruptured backing layer from the
associated formation, a part of the ruptured backing layer
remaining in contact with the flexible adhesive member and thereby
releasing the tablet.
The flexible adhesive member may include an adhesive coated tape
and the method may include the step of conveying the blister pack
on the tape between a depressing station where the formation is
depressed to rupture the backing layer and a backing layer removal
station where a part of the ruptured backing layer is removed from
the blister pack.
Means may be provided for drawing the adhesive coated tape through
the depressing station and the backing layer removal station. The
adhesive coated tape may be drawn over a carrier plate having a
substantially planar upper face, the tape passing over the carrier
plate with its adhesive coated face oriented away from the plate
such that a blister pack located on the carrier plate is received
on the adhesive coated face of the tape.
The method may include the step of conveying the blister pack on
the adhesive coated tape from the carrier plate to the depressing
station. The method may include the step of gripping an edge of the
blister pack in the depressing station. The method may include the
step of using a driven roller to grip an edge of the blister pack.
The method may further include the step of using the driven roller
to depress the formation to rupture the backing layer.
The method may further include the step of drawing the blister pack
on the adhesive coated tape to the backing layer removal station,
where the blister pack is guided away from the adhesive coated tape
towards a tablet collection receptacle.
An embodiment of the invention will be described for the purpose of
illustration only with reference to the accompanying drawings in
which:
FIG. 1A is a diagrammatic cross section through a blister pack and
FIG. 1B is a plan view of the blister pack of FIG. 1A;
FIG. 2 is a diagrammatic sectional view of a de-blistering
apparatus according to the invention; and
FIG. 3 is a plan view of the apparatus of FIG. 2.
Referring to FIGS. 1A and 1B, a blister pack 10 includes a moulded
plastics member formed to include a generally planar portion 12
provided with a plurality of substantially semi-cylindrical
formations 14 protruding therefrom. Within each formation 14, a
tablet 16 is received. The tablets 16 are sealed within the
formations 14 by a thin, rupturable foil member 18. To remove
tablets 16 from the blister pack 10, the foil 18 may be ruptured,
for example with a finger nail, to open up the formations 14.
FIGS. 2 and 3 illustrate a de-blistering apparatus 20 for removing
tablets 16 from blister packs 10. The de-blistering apparatus 20
works essentially by using an adhesive coated tape to mount and to
draw a blister pack 10 through a depressing station 22 and a foil
removal station 24. In the depressing station 22 the foil 18 which
seals the tablets 16 within the formations 14 is ruptured and in
the foil removal station 24 the ruptured foil 18 is removed from
the blister pack 10 to free the tablets 16.
At an upstream end of the de-blistering apparatus 20, there is
provided a cartridge 26 of adhesive coated tape 28. The adhesive
coated side of the tape 28 is located outwardly on the cartridge.
The tape 28 is made of polyvinylchloride and is about 0.11 mm
thick. It has a breaking load of about 20 N/cm and a maximum
elongation of about 120%. The adhesion of the tape to itself is
about 2.5 N/cm.
The cartridge 26 is mounted so as to be freely rotatable about an
axis 30.
Downstream of the cartridge 26, there is located a substantially
planar carrier plate 32. The carrier plate 32 is oriented
substantially horizontally when the apparatus 20 rests on a
horizontal surface. Above and spaced from the carrier plate 32 is a
guide roller 33. The guide roller 33 is free running and is made of
a soft material.
Adjacent to and downstream of the carrier plate 32, there is
provided a blister pack drive roller 34, which has a diameter of
about 8 mm and which is coated with non-stick silicon rubber. The
carrier plate 32 is slidable in the direction indicated by the
arrow A, in order adjust the horizontal distance 36 between a flat
edge 38 of the carrier plate 32 and the centre of the blister pack
drive roller 34.
The blister pack drive roller 34 may be driven to rotate in an
anti-clockwise direction as viewed in FIG. 2. The function of the
blister pack drive roller 34 is described in more detail
hereinafter.
The flat edge 38 of the carrier plate 32 and the blister pack drive
roller 34 together form the depressing station 22.
The foil removal station 24 is located downstream and somewhat
above the depressing station 22. The foil removal station 24
includes a free running guide roller 42, also having a diameter of
about 8 mm. Adjacent to the guide roller 42 is a platform member
44. An edge 46 of the platform member is located close to an outer
radius of the guide roller, but there is a gap of about 0.5 mm
therebetween.
Generally under the drive roller 34 there is provided a collector
roller 48 onto which the adhesive coated tape may be wound. The
collector roller 48 is driven such that it may rotate in a
clockwise direction as viewed in FIG. 2, thus drawing the tape 18
from the cartridge 26. The tape 18 so drawn passes over the carrier
plate 32, under the blister pack drive roller 34, over the guide
roller 42 and finally onto the collector roller 48. The collector
roller 48 includes a central driven member 49, having a diameter of
about 8 mm, and an outer tape receiving portion 51, having a
diameter of about 80 mm.
The platform member 44 forms an upper surface of a pill collection
container 50 provided with an upper orifice 52, which is sized such
that a typical blister pack 10 cannot pass therethrough but tablets
16 can pass therethrough.
Adjacent to the pill collection container 50, an empty pack
container 54 is provided.
The apparatus works as follows. A blister pack 10 (not shown in
FIG. 2) from which tablets 16 are to be removed is placed on the
tape 28 on the corner plate 32. The carrier plate 32 is adjusted
such that the horizontal distance 36 between the flat edge 38 of
the carrier plate and the blister pack drive roller 34 is
appropriate, as described in more detail below.
The collector roller 48 is driven in a clockwise direction to draw
tape 28 from the cartridge 26. As the tape 28 is drawn, the blister
pack 10 passes underneath the guide roller 33. The guide roller 33
is soft and presses the blister pack 10 lightly against the tape
28. In this way the best adhesion between the blister pack 10 and
the tape 28 is achieved.
The blister pack drive roller 34, which may be driven by a common
drive with the collector roller 48, rotates in an anti-clockwise
direction. The rotation of the blister pack drive roller 34 draws
an edge of the blister pack to the right as illustrated in FIG. 2,
the blister pack being held between the adhesive tape 28 and the
drive roller 34. As the blister pack 10 moves to the right, the
drive roller 34 encounters a formation 14 in the blister pack. As
the formation is drawn under the drive roller, the drive roller 34
depresses the formation 14 at its leading edge, causing the tablet
16 located within to pivot in a clockwise direction. The pivoting
action of the tablet 16 linked with the tape support causes the
foil 18 sealing the formation 14 to rupture. The tape is
sufficiently soft that the tablet 16 may partly protrude from the
blister pack when depressed, without unduly adding pressure which
may damage the tablet. The non-stick surface of the drive roller
ensures that the tape 28 does not stick to this roller.
The collector roller 48 continues to rotate, drawing the blister
pack 10 on the tape 28 up the angled portion of tape between the
depressing station 22 and the foil removal station 24. When the
next formation 14 or set of formations 14 encounters the blister
pack drive roller the formations 14 are depressed causing the
tablets 16 to pivot as described previously and thus rupturing the
associated pieces of foil 18.
The blister pack 10 subsequently encounters the foil removal
station 24. The blister pack 10 is relatively stiff and cannot pass
between the edge 46 of the platform member 44 and the guide roller
42. Thus, the blister pack is conveyed towards the pill collection
container 50. However, the ruptured foil 18 is firmly stuck on to
the tape 28. Thus, as the blister pack 10 moves towards the pill
collection container 50, a portion of foil 18 adjacent to each
formation 14 remains on the tape 28 and is torn from the remainder
of the blister pack 10. Thus, each formation 14 is now
unsealed.
The blister pack 10 subsequently passes over the orifice 52 of the
pill collection container. The orifice 52 is sized such that the
blister pack may not pass therethrough. However the tablets 16 now
in unsealed formations 14 drop out of the blister pack into the
pill collection container 50. The empty blister pack 10 is then
received within the empty pack container 54.
There is thus provided a de-blistering apparatus 20 which allows
for the convenient and quick removal of tablets 16 form blister
packs 10. The horizontal distance 36 between the flat edge 38 of
the carrier plate 32 may be adjusted to ensure that the apparatus
functions for all sizes of tablets 16.
There is thus provided improved apparatus for removing tablets from
blister packs. Prior art de-blistering techniques include the use
of a roller to push/expel tablets fully out of the blister pack.
The blister pack is mounted on a carrier, including gaps for
allowing the tablets to be pushed out. Because there are very large
numbers of different sizes and depths of tablets, generally an
individual carrier must be made for each type of pack formation or
adjustable locators or guides must be provided to allow alterations
for different depths and diameters of tablets. The arrangements can
prove ineffective for many types of blister packs.
The preferred apparatus and method according to the invention, as
described above, virtually removes the above problems. There is no
need to push the tablet out a particular depth as it is simply
necessary for the foil to break. The tape also acts as a support,
thus removing virtually all need for support from the carrier.
Various modifications may be made to the above described embodiment
without departing from the scope of the invention. For example, it
is not essential that the tape 28 passes over the carrier plate 32.
A tape cartridge could be located generally underneath the blister
pack drive roller 34, such that the blister pack only comes into
contact with the tape as the drive roller depresses a formation to
rupture the foil 18. The drive roller 34 may be driven
independently of the collector roller 48. The sizes, shapes and
general arrangement of the components may be varied.
The carrier plate 32 may be heated to increase adhesive "grab". The
tape may be heated by some other means, or pre-heated, to produce
an equivalent effect. The aluminium foil of the blister packs may
additionally or alternatively be pre-treated to increase adhesion
with the tape 28. For example, isopropylalcohol could be applied
via a spray or via a soft roller before the pack is presented to
the machine, or corona treatment could be used
The carrier plate 32 may comprise one of a set of three or more
alternative blocks (small, medium and large), that may be used to
vary the height of the planar surface to adjust the apparatus for
different sizes of tablet.
The drive roller 34 may be mounted on a hinged support such that it
may be pivoted between the position shown in FIG. 2 and a higher
position which allows for ease of mounting the tape.
Whilst endeavouring in the foregoing specification to draw
attention to those features of the invention believed to be of
particular importance it should be understood that the Applicant
claims protection in respect of any patentable feature or
combination of features hereinbefore referred to and/or shown in
the drawings whether or not particular emphasis has been placed
thereon.
* * * * *